Los Angeles County collects 33 billion gallons of rainwater in recent storms

[sopas ej]

From KTLA:

Los Angeles County collects 33 billion gallons of rainwater in recent storms

by: Travis Schlepp
Posted: Jan 16, 2023 / 12:36 PM PST
Updated: Jan 16, 2023 / 12:54 PM PST

Good news has surfaced in Los Angeles County’s ongoing battle with water scarcity.

The Los Angeles County Public Works Department announced Monday that more than 33 billion gallons of stormwater have been captured in the early months of the California winter storm season.

It will be used as drinking water and is enough to supply 816,000 people with enough water for an entire year, according to Los Angeles County Public Works Director Mark Pestrella.

“This is great news for the county and the region,” Pestrella said in a news release. “We’re working with our water partners to increase the region’s capacity to capture, clean and conserve stormwater runoff, while investing with equity in communities through the Safe Clean Water Program.”

L.A. County’s Public Works Department operates a regional stormwater network that includes 14 major dams and more than 620 miles of rivers and flood channels and 3,400 miles of underground storm drains.

The system is tasked with regional flood protection throughout the Los Angeles Basin and is responsible for recharging groundwater aquifers that supply about one-third of the area’s drinking water.

The Public Works Department also manages the Safe Clean Water Program, an initiative passed in 2018 that aims to increase local water supplies by capturing stormwater.

Several recapture projects have been completed since the adoption of the Safe Clean Water Program. So far, the projects have resulted in 228 million gallons of stormwater being collected each year.

More infrastructure projects are underway with funding through the program, Public Works officials said. Once completed, those projects are expected to provide capacity to serve an additional 500,000 people across L.A. County.

Link: https://ktla.com/news/local-news/los...recent-storms/

[LosAngelesSportsFan]

Every single spreading ground, river, lake, etc is full. It's beautiful to see

[dimondpark]

That is great news for LA. As far as up here, I am grateful for the 11 consecutive storms that pounded us succession for like 2 weeks-our state desperately needed all that water-but to be completely honest, I am **so** happy it's sunny today.

[sopas ej]

I'm so glad that they're finally capturing rainwater in LA County instead of letting most of it rush out to sea. Basically our water infrastructure was built in the first half of the 20th Century, when the climate was different from what it is today. It's nice to know we're adapting to reality.

And yeah, I'm actually looking out the window at work right now, and it's almost refreshing to see the sun. Not that I minded the cloudiness.

[JManc]

My coworker lives in LA and he's says he's never seen the LA River as high as it was.

[jd3189]

The hills are emerald green where I am right now. One of the great things about living here that I appreciate.

[202_Cyclist]

Let's see those photos of LA (the ones where you can see all the way from the ocean to the snow-capped local mountains) after the storms!

[edale]

I love to hear that LA is making strides in capturing storm water! Thank you for sharing the article. Winter is my favorite time in LA...I absolutely love when the hills turn bright green and everything feels fresh and verdant. However, the past month or so has felt like a slice of Ohio, with near constant cloudiness and only seeing the sun for a few days. It was honestly starting to get depressing, and I'm thankful for the bright sunshine today, too. I hope the rain won't stay away for too long though...we need more rain and snow through March to get out of the drought.

[jmecklenborg]

Originally Posted by JManc

My coworker lives in LA and he's says he's never seen the LA River as high as it was.

People need to remember that the reason why the LA River and similar creeks/rivers are channelized in concrete is to enable storm water to flow as quickly as possible. If the concrete were removed and the natural banks restored, it's likely that the railroad tracks that follow both sides of the river would have been washed away and thousands of commercial buildings would have been flooded.

https://www.youtube.com/watch?v=yf5_suAUKx4

[JManc]

Originally Posted by jmecklenborg

People need to remember that the reason why the LA River and similar creeks/rivers are channelized in concrete is to enable storm water to flow as quickly as possible. If the concrete were removed and the natural banks restored, it's likely that the railroad tracks that follow both sides of the river would have been washed away and thousands of commercial buildings would have been flooded.

https://www.youtube.com/watch?v=yf5_suAUKx4

I understand that. Much of Houston main waterways are built up in same way but Houston gets a lot of rain. LA is in the desert and the rivers tend to be mostly non existent.

[jmecklenborg]

Originally Posted by JManc

I understand that. Much of Houston main waterways are built up in same way but Houston gets a lot of rain. LA is in the desert and the rivers tend to be mostly non existent.

And unfortunately, throughout the Midwest, trees and undergrowth typically aren't allowed to grow on the earth levees, which gives places an eerie feel:https://www.google.com/maps/@39.7901...7i13312!8i6656

[Northern Light]

Originally Posted by jmecklenborg

People need to remember that the reason why the LA River and similar creeks/rivers are channelized in concrete is to enable storm water to flow as quickly as possible. If the concrete were removed and the natural banks restored, it's likely that the railroad tracks that follow both sides of the river would have been washed away and thousands of commercial buildings would have been flooded.

https://www.youtube.com/watch?v=yf5_suAUKx4

A problem easily resolved by moving the railway tracks (or elevating them on a viaduct) and removing development from the 25-year regulatory floodplain.

Managing stormwater via concrete precludes recharging aquifers and wetlands, it exacerbates the urban heat island effect, and eliminates habitat for most fish and amphibians.

Its just not the right move, never was.

There may be some spots where there is extensive development that is impractical or undesirable to relocate, but even then, there are are better alternatives, including creating a wet meadow upstream where excess water can be diverted.

LA has no shortage of environmentally regrettable golf courses which could be repurposed.

[JDRCRASH]

Originally Posted by JManc

I understand that. Much of Houston main waterways are built up in same way but Houston gets a lot of rain. LA is in the desert and the rivers tend to be mostly non existent.

Additionally, the LA River has a way steeper descent from the headwaters to the mouth. It descends 800 ft of elevation in around 50 miles, with an average slope of 0.29 percent.

https://www.waterboards.ca.gov/losan...pendix%20A.pdf

There just isn't time to let that water percolate into the already dry ground.

[edale]

Originally Posted by Northern Light

A problem easily resolved by moving the railway tracks (or elevating them on a viaduct) and removing development from the 25-year regulatory floodplain.

Managing stormwater via concrete precludes recharging aquifers and wetlands, it exacerbates the urban heat island effect, and eliminates habitat for most fish and amphibians.

Its just not the right move, never was.

There may be some spots where there is extensive development that is impractical or undesirable to relocate, but even then, there are are better alternatives, including creating a wet meadow upstream where excess water can be diverted.

LA has no shortage of environmentally regrettable golf courses which could be repurposed.

In most cases, I think you're correct. But this post demonstrates a poor understanding of the LA River and Southern California's hydrology.

The LA River isn't really a river in the traditional sense that people think of rivers. It's more of a drainage corridor, and it would run dry most of the year if not for artificial sources in the dry months. There really isn't a fixed course or discernible banks of the river, and prior to channelization, it would wildly change course during large rain events.

If the LA basin wasn't urbanized, water flowing out of the mountains would fan out across the basin creating a series of wetlands in lower lying areas after rain events. You can see the alluvial fan pattern on the north side of the mountains in the sparsely populated high desert. That obviously isn't possible given the urbanization of LA, so instead, water has to be channelized into predictable drainage patterns. The LA River is fed by many of these channelized streams or arroyos, and when it rains, water rushes at extreme volumes and speeds, and much of it gets dumped out into the ocean. It's an entirely different scenario than water patterns in the eastern half of the country.

[Yuri]

Does someone have pics of the new landscape?

[TWAK]

Water levels for Clear Lake and it's natural, so the decline during the summer is not as bad as the reservoirs.

The question is, how much rainfall did Nor Cal get for Kern County?

[Northern Light]

Originally Posted by edale

In most cases, I think you're correct. But this post demonstrates a poor understanding of the LA River and Southern California's hydrology.

The LA River isn't really a river in the traditional sense that people think of rivers. It's more of a drainage corridor, and it would run dry most of the year if not for artificial sources in the dry months. There really isn't a fixed course or discernible banks of the river, and prior to channelization, it would wildly change course during large rain events.

If the LA basin wasn't urbanized, water flowing out of the mountains would fan out across the basin creating a series of wetlands in lower lying areas after rain events. You can see the alluvial fan pattern on the north side of the mountains in the sparsely populated high desert. That obviously isn't possible given the urbanization of LA, so instead, water has to be channelized into predictable drainage patterns. The LA River is fed by many of these channelized streams or arroyos, and when it rains, water rushes at extreme volumes and speeds, and much of it gets dumped out into the ocean. It's an entirely different scenario than water patterns in the eastern half of the country.

I appreciate what your saying, though perhaps I didn't make my level of understanding clear, I have done work in ecological restoration including flood mitigation.

I understand water conveyance and storage.

What I have in mind can be illustrated very easily through the LA Country Flood Zone Map:

https://apps.gis.lacounty.gov/dpw/m/?viewer=floodzone

What you see is the area waters would naturally go to, as you suggest, some along channels, some in (naturally) wetlands/ponds/lakes/wet meadows etc.

Clearly, much as I might like to see, all of the urbanization in the affected areas is not going to be removed.

But some of it mostly certainly can be. You buy out the most risk-affected properties, particularly where there is a critical mass that can restore the original ecological function of the area.

When you do that, you will reduce peak-conveyance in the LA River flood channel, affording room (in some spots) for renaturalization.

Pick 5 key spots, remove 1,000 acres of urbanity and let nature do her thing. Expensive yes, (but so are disasters and so is drought). Just phase the changes over time.

Some of the secondary locations can be served by natural channels (which may well be dry for 1/2 the year); but could, alternatively be delivered water by piped conveyance from where its a problem, to where its useful.

[TWAK]

^Aren't there plants that uphold levees? I think in Sac they have planted specific succulents.

[ChrisLA]

Originally Posted by JManc

My coworker lives in LA and he's says he's never seen the LA River as high as it was.

I have seen it this high and even higher over the years. Your co-worker is either young or hasn’t lived in L.A very long. It’s not like we don’t have a very wet and rainy season.

https://www.laalmanac.com/weather/we08ba.php

Wettest Seasons (Period: July 1 to June 30 of following year)
Since first recorded rain season, 1877-1878

Total Inches of Rainfall Season
38.18 1883-1884
37.25 2004-2005
34.84 1889-1890
33.44 1977-1978
32.76 1940-1941
31.25 1982-1983
31.01 1997-1998
27.47 1968-1969
27.36 1992-1993
26.98 1978-1980

[SFBruin]

This is great!